Lens and lens assembly including the same

ABSTRACT

A lens includes an optical portion refracting light, a rib extending along a circumference of at least a portion of the optical portion, a first area and a second area of an object-side surface of the rib, wherein the first area has a first surface roughness and the second area has a second surface roughness less rough than the first surface roughness, and a third area and a fourth area of an image-side surface of the rib, wherein the third area has a third surface roughness and the fourth area has a fourth surface roughness less rough than the third surface roughness, wherein the second area includes inclined surfaces.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 USC 119(a) of Korean PatentApplication No. 10-2018-0116201 filed on Sep. 28, 2018, in the KoreanIntellectual Property Office, the entire disclosure of which isincorporated herein by reference for all purposes.

BACKGROUND 1. Field

This application relates to a lens and a lens assembly including thesame.

2. Description of the Background

Camera modules have been recently used in portable electronic devicessuch as smartphones.

Such camera modules include a lens assembly including a plurality oflenses. Recently, the number of lenses has been increased in order toimprove performance of the camera modules and the camera modules havedecreased in size.

That is, the size of camera modules has decreased, while the number oflenses has increased. As a result, it has become more difficult to alignoptical axes of the plurality of lenses with each other.

Further, there may be a problem in that unintended light reflection mayoccur in the camera module, and the unintendedly reflected light, lightirrelevant to image formation, may cause a flare or ghost phenomenon ina photographed image.

The above information is presented as background information only toassist with an understanding of the present disclosure. No determinationhas been made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the disclosure.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

In one general aspect, a lens includes an optical portion refractinglight, a rib extending along a circumference of at least a portion ofthe optical portion, a first area and a second area of an object-sidesurface of the rib, wherein the first area has a first surface roughnessand the second area has a second surface roughness less rough than thefirst surface roughness, and a third area and a fourth area of animage-side surface of the rib, wherein the third area has a thirdsurface roughness and the fourth area has a fourth surface roughnessless rough than the third surface roughness, wherein the second areaincludes inclined surfaces.

At least portions of the second area and the fourth area may overlapeach other when viewed in an optical axis direction.

The inclined surfaces may include different angles of inclination fromeach other.

The inclined surfaces may meet at a first edge portion.

A second edge portion may be formed in the fourth area.

The first edge portion and the second edge portion may be disposed in aregion in which the second area and the fourth area overlap each otherwhen viewed in the optical axis direction.

A length between the first edge portion and an end of the rib may bedifferent from a length between the second edge portion and the end ofthe rib.

The first area and the second area may be alternately formed from oneside end of the rib to the other side end of the rib.

The first area may be disposed on each of both sides of the second area.

The lens may further include a first protrusion disposed in the firstarea protruding in the optical axis direction and a second protrusiondisposed in the third area protruding opposite to the first protrusionin the optical axis direction.

An end of the rib may have a surface roughness corresponding to that ofthe first area, the second area, the third area, or the fourth area.

In another general aspect, a lens assembly includes lenses disposedalong an optical axis and each of the lenses including an opticalportion refracting light and a rib extending along a circumference of atleast a portion of the optical portion, and a lens barrel in which thelenses are accommodated, wherein an object-side surface of the rib of atleast one of the lenses includes a first area and a second area havingdifferent surface roughnesses, wherein the first area is disposed to becloser to the optical portion than the second area and is rougher thanthe second area, and wherein the second area includes inclined surfaces.

An image-side surface of the rib of the at least one lens may include athird area and a fourth area having different surface roughnesses. Thethird area may be disposed to be closer to the optical portion than thefourth area and may be rougher than the fourth area.

At least portions of the second area and the fourth area may overlapeach other when viewed in an optical axis direction.

The second area and the fourth area each may include an edge portion,and the edge portion may be disposed in a region in which the secondarea and the fourth area overlap each other in the optical axisdirection.

The ribs of two adjacent lenses may be coupled to one another.

A spacer may be disposed between the ribs of the two adjacent lensescoupled to one another.

In another general aspect, a lens includes an object-side surface and animage-side surface, an optical portion having an optical axis, and a ribextending along a circumference of the optical portion, the ribincluding a first circumferential region and a second circumferentialregion having lower surface roughness than the first circumferentialregion on the object-side and the image-side surfaces, wherein thesecond circumferential region overlaps on the object-side and theimage-side surfaces in an optical axis direction in proportion toconcentricity of the of the object-side surface and the image-sidesurface.

The second circumferential region may include a circumferential edgeportion.

The second circumferential region may include a first circumferentialedge portion disposed on the object-side and a second circumferentialedge portion disposed on the image-side, wherein the firstcircumferential edge portion may be spaced apart from the secondcircumferential edge portion in a direction perpendicular to the opticalaxis direction in proportion to concentricity of the object-side surfaceand the image-side surface.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic cross-sectional view of a lens assembly accordingto one or more examples.

FIG. 2 is a schematic cross-sectional view of a lens according to one ormore examples.

FIG. 3 is an enlarged cross-sectional view of a portion of a rib of alens according to one or more examples.

FIGS. 4 and 5 are enlarged cross-sectional views of portions of ribs oflenses according to one or more other examples.

FIG. 6 is an enlarged cross-sectional view of a portion of a rib of alens according to one or more still other examples.

Throughout the drawings and the detailed description, the same referencenumerals refer to the same elements. The drawings may not be to scale,and the relative size, proportions, and depiction of elements in thedrawings may be exaggerated for clarity, illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. However, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein will be apparent after an understanding of thedisclosure of this application. For example, the sequences of operationsdescribed herein are merely examples, and are not limited to those setforth herein, but may be changed as will be apparent after anunderstanding of the disclosure of this application, with the exceptionof operations necessarily occurring in a certain order. Also,descriptions of features that are known in the art may be omitted forincreased clarity and conciseness.

The features described herein may be embodied in different forms, andare not to be construed as being limited to the examples describedherein. Rather, the examples described herein have been provided merelyto illustrate some of the many possible ways of implementing themethods, apparatuses, and/or systems described herein that will beapparent after an understanding of the disclosure of this application.Hereinafter, while embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings, it isnoted that examples are not limited to the same.

Throughout the specification, when an element, such as a layer, region,or substrate, is described as being “on,” “connected to,” or “coupledto” another element, it may be directly “on,” “connected to,” or“coupled to” the other element, or there may be one or more otherelements intervening therebetween. In contrast, when an element isdescribed as being “directly on,” “directly connected to,” or “directlycoupled to” another element, there can be no other elements interveningtherebetween.

As used herein, the term “and/or” includes any one and any combinationof any two or more of the associated listed items; likewise, “at leastone of” includes any one and any combination of any two or more of theassociated listed items.

Although terms such as “first,” “second,” and “third” may be used hereinto describe various members, components, regions, layers, or sections,these members, components, regions, layers, or sections are not to belimited by these terms. Rather, these terms are only used to distinguishone member, component, region, layer, or section from another member,component, region, layer, or section. Thus, a first member, component,region, layer, or section referred to in examples described herein mayalso be referred to as a second member, component, region, layer, orsection without departing from the teachings of the examples.

Spatially relative terms such as “above,” “upper,” “below,” and “lower”may be used herein for ease of description to describe one element'srelationship to another element as shown in the figures. Such spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. For example, if the device in the figures is turned over,an element described as being “above” or “upper” relative to anotherelement will then be “below” or “lower” relative to the other element.Thus, the term “above” encompasses both the above and below orientationsdepending on the spatial orientation of the device. The device may alsobe oriented in other ways (for example, rotated 90 degrees or at otherorientations), and the spatially relative terms used herein are to beinterpreted accordingly.

The terminology used herein is for describing various examples only, andis not to be used to limit the disclosure. The articles “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. The terms “comprises,” “includes,”and “has” specify the presence of stated features, numbers, operations,members, elements, and/or combinations thereof, but do not preclude thepresence or addition of one or more other features, numbers, operations,members, elements, and/or combinations thereof.

Due to manufacturing techniques and/or tolerances, variations of theshapes shown in the drawings may occur. Thus, the examples describedherein are not limited to the specific shapes shown in the drawings, butinclude changes in shape that occur during manufacturing.

The features of the examples described herein may be combined in variousways as will be apparent after an understanding of the disclosure ofthis application. Further, although the examples described herein have avariety of configurations, other configurations are possible as will beapparent after an understanding of the disclosure of this application.

Herein, it is noted that use of the term “may” with respect to anexample, for example, as to what an example may include or implement,means that at least one example exists in which such a feature isincluded or implemented while all examples are not limited thereto.

An aspect of the present disclosure may provide a lens and a lensassembly including the same, capable of preventing light reflection fromoccurring and enabling easy measurement of concentricity of the lens.

FIG. 1 is a schematic cross-sectional view of a lens assembly accordingto one or more examples and FIG. 2 is a schematic cross-sectional viewof a lens according to one or more examples.

Referring to FIG. 1, a lens assembly 100 in the examples describedherein may include a plurality of lenses arranged along an optical axis.Further, the lens assembly 100 may further include a lens barrel B inwhich the plurality of lenses are accommodated. The plurality of lensesmay be arranged to be spaced apart from one another by preset distancesalong the optical axis.

The plurality of lenses may include five or more lenses. For example,the plurality of lenses according to the present example may include afirst lens L1, a second lens L2, a third lens L3, a fourth lens L4, afifth lens L5, a sixth lens L6, and a seventh lens L7 arranged to faceupward from an object side along the optical axis.

The first lens L1 may refer to a lens closest to an object (or asubject), while the seventh lens L7 may refer to a lens closest to animage sensor.

However, embodiments of the present disclosure are not limited by thenumber of lenses.

Each lens may include an optical portion 10 and a rib 20 (FIG. 2).

The optical portion 10 may be a part for optical performance of thelens. For example, light reflected from the object (or subject) may berefracted while passing through the optical portion 10.

The rib 20 may be a component for fixing the lens to another component,for example, the lens barrel B or another lens. The rib 20 may extend ata circumference of at least a portion of the optical portion 10, and maybe formed integrally with the optical portion 10.

The lens assembly 100 may include a self-aligning structure. That is,the lens assembly 100 may include a structure in which at least some ofthe plurality of lenses are coupled to one another so that optical axesthereof are aligned with each other.

For example, the optical axes may be aligned with each other by couplingfive lenses to one another as illustrated in FIG. 1.

Here, the first lens L1 disposed to be closest to the object side may bein contact with the lens barrel B to align an optical axis thereof, andthe second to fifth lenses L2 to L5 may be coupled to other lensesadjacent to the object side (for example, the first to fourth lenses L1to L4), respectively, to align optical axes thereof with each other.

For example, the first lens L1 and the second lens L2 may be coupled toeach other, the second lens L2 and the third lens L3 may be coupled toeach other, the third lens L3 and the fourth lens L4 may be coupled toeach other, and the fourth lens L4 and the fifth lens L5 may be coupledto each other.

That is, the ribs 20 of the first to fifth lenses L1 to L5 may becoupled to one another so that the optical axes of the respective lensesare aligned with each other. The rib 20 of each lens may include arugged structure, and rugged structures of the adjacent lenses may becoupled to one another to align the optical axes of the lenses with eachother.

Alternatively, all lenses of the lens assembly 100 may be coupled to oneanother to align optical axes thereof with each other, more than fivelenses may be coupled to one another to align optical axes thereof witheach other, or less than five lenses may be coupled to one another toalign optical axes thereof with each other.

Spacers may each be provided between lenses adjacent to each other. Atleast a portion of the rib 20 of each lens may be in contact with thespacer. The spacer may maintain an interval between the lenses, andblock unnecessary light.

The spacers may include a first spacer S1, a second spacer S2, a thirdspacer S3, a fourth spacer S4, a fifth spacer S5, a sixth spacer S6, anda seventh spacer S7 arranged toward the image sensor from the objectside.

The first spacer S1 may be disposed between the first lens L1 and thesecond lens L2, the second spacer S2 may be disposed between the secondlens L2 and the third lens L3, the third spacer S3 may be disposedbetween the third lens L3 and the fourth lens L4, the fourth spacer S4may be disposed between the fourth lens L4 and the fifth lens L5, thefifth spacer S5 may be disposed between the fifth lens L5 and the sixthlens L6, and the sixth spacer S6 may be disposed between the sixth lensL6 and the seventh lens L7. The seventh spacer S7 may also be disposedbetween the sixth lens L6 and the seventh lens L7.

The sixth spacer S6 may be formed to have the largest thickness amongthe plurality of spacers. For example, a thickness of the sixth spacerS6 in an optical axis direction may be larger than those of otherspacers in the optical axis direction.

FIG. 3 is an enlarged cross-sectional view of a portion of a rib of alens according to one or more examples.

The lens in the examples described herein may be formed of a plasticmaterial and may be injection-molded by injecting a resin material intoa mold.

The lens may include an object-side surface (a surface facing the objectside) and an image-side surface (a surface facing the image sensor).When the center of the object-side surface and the center of theimage-side surface do not coincide with each other, it is difficult toalign the optical axis with an optical axis of another lens, and imagequality of a photographed image deteriorates. Therefore, there is a needto precisely measure concentricity of the object-side surface and theimage-side surface of the injection-molded lens.

Meanwhile, light reflected from the object (or subject) is refractedwhile passing through the lens. In this case, unintended lightreflection may occur. The unintendedly reflected light which is lightirrelevant to image formation may cause a flare phenomenon in thephotographed image.

The lens in the examples described herein may suppress the flarephenomenon from occurring even when the unintended light reflectionoccurs, and enable easy measurement of concentricity of the object-sidesurface and the image-side surface.

The object-side surface of the rib 20 of the lens in the examplesdescribed herein may include a first area CA1 having first surfaceroughness and a second area NCA1 having second surface roughness.

The image-side surface of the rib 20 of the lens in the examplesdescribed herein may include a third area CA2 having third surfaceroughness and a fourth area NCA2 having fourth surface roughness.

The surface roughness of the first area CA1 may be different from thatof the second area NCA1, and the surface roughness of the third area CA2may be different from that of the fourth area NCA2.

As an example, the first area CA1 may be rougher than the second areaNCA1 and the third area CA2 may be rougher than the fourth area NCA2.

The first area CA1 and the third area CA2 may have surface roughnessescorresponding to each other and the second area NCA1 and the fourth areaNCA2 may have surface roughnesses corresponding to each other.

The first and third areas CA1 and CA2 may be corroded areas and may beformed by chemical etching or physical polishing. Therefore, the firstand third areas CA1 and CA2 may diffuse reflected light.

Accordingly, even when unintended light reflection occurs, the reflectedlight may not be concentrated on a point, thereby suppressing occurrenceof the flare phenomenon.

The second area NCA1 and the fourth area NCA2 may not besurface-treated, or even in the case in which the second area NCA1 andthe fourth area NCA2 are surface-treated, the surface roughnesses of thesecond and fourth areas NCA1 and NCA2 may be different from those of thefirst and third areas CA1 and CA2. As an example, the second and fourthareas NCA1 and NCA2 may have lower surface roughnesses (i.e., be lessrough, be smoother) than the first and third areas CA1 and CA2.

The first area CA1 and the second area NCA1 may be alternately formed onthe object-side surface of the rib 20 of the lens.

As an example, the first area CA1, the second area NCA1, and the firstarea CA1 may be sequentially formed from one side end (a portion incontact with the optical portion 10) of the object-side surface of therib 20 of the lens to the other side end (a portion in contact with anoutermost side surface 25 of the lens) of the object-side surface of therib 20 of the lens. That is, the first area CA1 may be disposed on eachof both sides of the second area NCA1.

One of the first areas CA1 may be disposed to be closer to the opticalportion 10 than the second area NCA1.

A protrusion 21 may be provided on the object-side surface of the rib 20of the lens, and the first area CA1 may be continuously formed in aregion including the protrusion 21 from the one side end of theobject-side surface of the rib 20 of the lens.

In addition, the first area CA1 may also be formed in a portion wherethe object-side surface of the lens is in contact with the outermostside surface 25 of the lens.

An area of the first area CA1 may be larger than that of the second areaNCA1 on the object-side surface of the rib 20 of the lens.

The second area NCA1 formed between the first areas CA1 may include aplurality of inclined surfaces 21-1 and 21-2 having different angles ofinclination. A first edge portion E1 may be formed at a portion wherethe plurality of inclined surfaces 21-1 and 21-2 meet each other.

The third area CA2 and the fourth area NCA2 may be alternately formed onthe image-side surface of the rib 20 of the lens. As an example, thethird area CA2 and the fourth area NCA2 may be sequentially formed fromone side end (a portion in contact with the optical portion 10) of theimage-side surface of the rib 20 of the lens to the other side end (aportion in contact with the outermost side surface 25 of the lens) ofthe image-side surface of the rib 20 of the lens.

The third area CA2 may be disposed to be closer to the optical portion10 than the fourth area NCA2.

A protrusion 23 may be provided on the image-side surface of the rib 20of the lens, and the third area CA2 may be continuously formed in aregion including the protrusion 23 from the one side end of theimage-side surface of the rib 20 of the lens.

An area of the third area CA2 may be larger than that of the fourth areaNCA2 on the image-side surface of the rib 20 of the lens.

The fourth area NCA2 may include a second edge portion E2.Alternatively, the fourth area NCA2 may include the second edge portionE2 and a third edge portion E3. The second and third edge portions E2and E3 may also mean a portion where inclined surfaces having differentangles of inclination meet each other. Alternatively, the second andthird edge portions E2 and E3 may mean a portion where an inclinedsurface and a horizontal surface (a surface perpendicular to the opticalaxis) meet each other.

Here, at least portions of the second area NCA1 and the fourth area NCA2may overlap each other when viewed in the optical axis direction.

In addition, the first edge portion E1 and the second edge portion E2(and/or the third edge portion E3) may be disposed in the overlappedregion.

A length D1 (a shortest distance in a direction perpendicular to theoptical axis) between the outermost surface 25 (the end of the rib 20)of the lens and the first edge portion E1 and a length D2 (and/or D3) (ashortest distance in the direction perpendicular to the optical axis)between the outermost surface 25 (the end of the rib 20) of the lens andthe second edge portion E2 (and/or the third edge portion E3) may bedifferent from each other.

As an example, the length D1 between the outermost surface 25 of thelens and the first edge portion E1 may be larger than the length D2(and/or D3) between the outermost surface 25 of the lens and the secondedge portion E2 (and/or the third edge portion E3).

The first edge portion E1 and the second edge portion E2 (and/or thethird edge portion E3) may be disposed in a region in which the secondarea NCA1 and the fourth area NCA2 overlap each other in the opticalaxis direction, thereby easily measuring concentricity of the lens.

Meanwhile, in the present example, the outermost surface 25 of the lensmay have a surface roughness corresponding to that of the second areaNCA1 or the fourth area NCA2.

At least one of the plurality of lenses provided in the lens assembly100 in the examples described herein may be a lens described withreference to FIG. 3. As an example, the lens described with reference toFIG. 3 may be a lens disposed to be closest to the image sensor amongthe plurality of lenses.

FIGS. 4 and 5 are enlarged cross-sectional views of portions of ribs oflenses according to one or more other examples described herein.

The example of FIG. 4 is the same as the example of FIG. 3, except forthe outermost surface 25 of the lens, and the outermost surface 25 ofthe lens in the example of FIG. 4 may have a surface roughnesscorresponding to that of the first area CA1 or the third area CA2.

The example of FIG. 5 is the same as the example of FIG. 3, except forthe protrusion 21 of the object-side surface of the rib 20 of the lens,and a surface of the protrusion 21 of the object-side surface of the rib20 of the lens, which is closest to the object side may have a surfaceroughness corresponding to that of the second area NCA1 or the fourtharea NCA2. The surface closest to the object side may be a surface indirect contact with another component (for example, the spacer oranother lens).

FIG. 6 is an enlarged cross-sectional view of a portion of a rib of alens according to another example in the examples described herein.

A first area CA1 and a second area NCA1 may be alternately formed on anobject-side surface of a rib 20 of a lens. As an example, the first areaCA1, the second area NCA1, and the first area CA1 may be sequentiallyformed from one side end (a portion in contact with an optical portion10) of the object-side surface of the rib 20 of the lens to the otherside end (a portion in contact with an outermost side surface 25 of thelens) of the object-side surface of the rib 20 of the lens. That is, thefirst area CA1 may be disposed on each of both sides of the second areaNCA1.

One of the first areas CA1 may be disposed to be closer to the opticalportion 10 than the second area NCA1.

A protrusion 21 may be provided on the object-side surface of the rib 20of the lens, and the first area CA1 may be continuously formed in aregion including the protrusion 21 from the one side end of theobject-side surface of the rib 20 of the lens.

In addition, the first area CA1 may also be formed in a portion wherethe object-side surface of the lens is in contact with the outermostside surface 25 of the lens.

An area of the first area CA1 may be larger than that of the second areaNCA1 on the object-side surface of the rib 20 of the lens.

The second area NCA1 formed between the first areas CA1 on theobject-side surface may include a plurality of inclined surfaces 21-1and 21-2 having different angles of inclination. A first edge portion E1may be formed at a portion where the plurality of inclined surfaces 21-1and 21-2 meet each other.

A third area CA2 and a fourth area NCA2 may be alternately formed on animage-side surface of the rib 20 of the lens. As an example, the thirdarea CA2, the fourth area NCA2, and the third area CA2 may besequentially formed from one side end (a portion in contact with theoptical portion 10) of the image-side surface of the rib 20 of the lensto the other side end (a portion in contact with the outermost sidesurface 25 of the lens) of the image-side surface of the rib 20 of thelens. That is, the third areas CA2 may be disposed at both sides of thefourth area NCA2.

One of the third areas CA2 may be disposed to be closer to the opticalportion 10 than the fourth area NCA2.

A protrusion 23 may be provided on the image-side surface of the rib 20of the lens, and the third area CA2 may be continuously formed in aregion including the protrusion 23 from the one side end of theimage-side surface of the rib 20 of the lens.

In addition, the third area CA2 may also be formed in a portion wherethe image-side surface of the lens is in contact with the outermost sidesurface 25 of the lens.

An area of the third area CA2 may be larger than that of the fourth areaNCA2 on the image-side surface of the rib 20 of the lens.

The fourth area NCA2 formed between the third areas CA2 on theimage-side surface may include a second edge portion E2. The second edgeportion E2 may also mean a portion where inclined surfaces havingdifferent angles of inclination meet each other. Alternatively, thesecond edge portion E2 may mean a portion where an inclined surface anda horizontal surface (a surface perpendicular to the optical axis) meeteach other.

Here, at least portions of the second area NCA1 formed on theobject-side surface of the lens and the fourth area NCA2 formed on theimage-side surface of the lens may overlap each other when viewed in theoptical axis direction.

In addition, the first edge portion E1 and the second edge portion E2may be disposed in the overlapped region.

A length D1 (a shortest distance in a direction perpendicular to theoptical axis) between the outermost surface 25 of the lens and the firstedge portion E1 and a length D2 (a shortest distance in the directionperpendicular to the optical axis) between the outermost surface 25 ofthe lens and the second edge portion E2 may be different from eachother.

As an example, the length D1 between the outermost surface 25 of thelens and the first edge portion E1 may be smaller than the length D2between the outermost surface 25 of the lens and the second edge portionE2.

The first edge portion E1 and the second edge portion E2 may be disposedin a region in which the second area NCA1 and the fourth area NCA2overlap each other in the optical axis direction, thereby easilymeasuring concentricity of the lens.

Meanwhile, in the present exemplary embodiment, the outermost surface 25of the lens may have a surface roughness corresponding to that of thesecond area NCA1 or the fourth area NCA2.

As set forth above, in the examples described herein, the lens and thelens assembly including the same are capable of preventing lightreflection from occurring, and concentricity of the lens may be easilymeasured.

While exemplary embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentinvention as defined by the appended claims.

What is claimed is:
 1. A lens, comprising: an optical portion refractinglight; a rib extending along a circumference of at least a portion ofthe optical portion; a first area and a second area of an object-sidesurface of the rib, wherein the first area comprises a first surfaceroughness and the second area comprises a second surface roughness lessrough than the first surface roughness; and a third area and a fourtharea of an image-side surface of the rib, wherein the third areacomprises a third surface roughness and the fourth area comprises afourth surface roughness less rough than the third surface roughness,wherein the second area comprises inclined surfaces.
 2. The lens ofclaim 1, wherein at least portions of the second area and the fourtharea overlap each other when viewed in an optical axis direction.
 3. Thelens of claim 2, wherein the inclined surfaces comprise different anglesof inclination from each other.
 4. The lens of claim 3, wherein theinclined surfaces meet at a first edge portion.
 5. The lens of claim 4,wherein a second edge portion is formed in the fourth area.
 6. The lensof claim 5, wherein the first edge portion and the second edge portionare disposed in a region in which the second area and the fourth areaoverlap each other when viewed in the optical axis direction.
 7. Thelens of claim 5, wherein a length between the first edge portion and anend of the rib is different from a length between the second edgeportion and the end of the rib.
 8. The lens of claim 1, wherein thefirst area and the second area are alternately formed from one side endof the rib to the other side end of the rib.
 9. The lens of claim 8,wherein the first area is disposed on each of both sides of the secondarea.
 10. The lens of claim 1, further comprising a first protrusiondisposed in the first area protruding in the optical axis direction anda second protrusion disposed in the third area protruding opposite tothe first protrusion in the optical axis direction.
 11. The lens ofclaim 1, wherein an end of the rib comprises a surface roughnesscorresponding to that of the first area, the second area, the thirdarea, or the fourth area.
 12. A lens assembly, comprising: lensesdisposed along an optical axis and each of the lenses comprising anoptical portion refracting light and a rib extending along acircumference of at least a portion of the optical portion; and a lensbarrel in which the lenses are accommodated, wherein an object-sidesurface of the rib of at least one of the lenses comprises a first areaand a second area having different surface roughnesses, wherein thefirst area is disposed to be closer to the optical portion than thesecond area and is rougher than the second area, and wherein the secondarea comprises inclined surfaces.
 13. The lens assembly of claim 12,wherein an image-side surface of the rib of the at least one lenscomprises a third area and a fourth area comprising different surfaceroughnesses, and wherein the third area is disposed to be closer to theoptical portion than the fourth area and is rougher than the fourtharea.
 14. The lens assembly of claim 13, wherein at least portions ofthe second area and the fourth area overlap each other when viewed in anoptical axis direction.
 15. The lens assembly of claim 14, wherein thesecond area and the fourth area each comprise an edge portion, and theedge portion is disposed in a region in which the second area and thefourth area overlap each other in the optical axis direction.
 16. Thelens assembly of claim 12, wherein the ribs of two adjacent lenses arecoupled to one another.
 17. The lens assembly of claim 16, furthercomprising a spacer disposed between the ribs of the two adjacent lensescoupled to one another.
 18. A lens, comprising: an object-side surfaceand an image-side surface; an optical portion comprising an opticalaxis; and a rib extending along a circumference of the optical portion,the rib comprising a first circumferential region and a secondcircumferential region comprising lower surface roughness than the firstcircumferential region on the object-side and the image-side surfaces,wherein the second circumferential region overlaps on the object-sideand the image-side surfaces in an optical axis direction in proportionto concentricity of the of the object-side surface and the image-sidesurface.
 19. The lens of claim 18, wherein the second circumferentialregion comprises a circumferential edge portion.
 20. The lens of claim18, wherein the second circumferential region comprises a firstcircumferential edge portion disposed on the object-side and a secondcircumferential edge portion disposed on the image-side, wherein thefirst circumferential edge portion is spaced apart from the secondcircumferential edge portion in a direction perpendicular to the opticalaxis direction in proportion to concentricity of the object-side surfaceand the image-side surface.